High temperature thermoelectric and magnetic properties of InxNdyCo4Sb12 skutterudites

We report high temperature thermoelectric properties in double-filled skutterudites InxNdyCo4Sb12. It is found that indium (In) and neodymium (Nd) double filling leads to enhanced Seebeck coefficient and electrical conductivity. The double filling of In and Nd can enhance power factor greatly. In the In0.16Nd0.06Co4Sb11.93 system, the largest power factor reaches 2.9 mW m−1 K−2 (613 K), which is about four times larger than that of InxCo4Sb12 (x≤0.3). Magnetic measurements reveal that the samples exhibit a paramagnetic moment developed at low temperature, which could be ascribed to Nd with a magnetic f3 state (S=3/2). This study indicates that In and Nd double filling is indeed more efficient in improving thermoelectric properties of CoSb3 skutterudite.